This invention relates to electromagnetic energy collection, and more particularly, to devices useful in the collection and utilization of radiant energy from solar sources. While the invention is described with particular emphasis in respect to its solar energy source collection application, those skilled in the art will recognize the wider applicability of the inventive principles disclosed hereinafter.
The prior art reveals a number of the devices adapted to concentrate available solar energy and convert that energy to perform useful work. In general, the concentrators may be classified as stationary or movable devices. Stationary devices either are moved manually to follow the energy source, or have special physical constructions which enables the device to gather some percentage of the available solar radiation regardless of the position of the sun, without physical movement of the concentrator. In the last mentioned case of the stationary concentrator, rather elaborate and complex reflector or lens designs are necessary in order to permit the stationary concentrator to accomplish its function.
Prior art concentrators which track the sun, on the other hand, as a class generally use complex electrical and mechanical devices to accomplish the tracking function. For example, photo cells and associated circuits and drivers commonly are employed for this purpose. At their present stage of development, known devices for tracking and concentrating the energy of the sun are relatively expensive to manufacture and maintain.
The invention disclosed hereinafter eliminates these prior art deficiencies by providing a low-cost means and method for tracking solar movement. In the preferred embodiment, tracking is provided by a serpentine shaped expanding means, preferably a bimetal, connected to a concentrator and adapted to receive concentrated energy from the concentrator in disaligned positions of the concentrator, so that it expands and drives the concentrator toward alignment with a solar source. At alignment, the concentrated energy is directed toward a suitable energy conversion means. The bimetal shape utilized for tracking, being temperature or radiant energy sensitive, continually interacts with the available energy supply so that the concentrator follows the energy source, once alignment is attained. For the purposes of this specification, the term "serpentine" is defined to mean the shape given an expanding means so that the expanding means gives relatively large movement with relatively small energy input at an aligned point of maximum energy concentration of the concentrator in order to hold the concentrator in alignment with the energy source while using only a small portion of the available energy; the shape of the expanding means at points other than the aligned point of maximum energy concentration being such as to receive energy from the concentrator, thereby causing the expansion means to move the concentrator back toward the aligned point of maximum energy concentration.
One of the objects of this invention is to provide a low-cost energy conversion device.
Another object of this invention is to provide a simplified device for tracking a source of radiant energy.
Still another object of this invention is to provide a source trackable solar concentrator driven by a suitable heat expandable device.
Yet another object of this invention is to provide a predeterminedly formed expansion device operatively connected to a concentrator of solar energy which is adapted to position the concentrator properly with respect to the solar energy source.
Other objects of this invention will be apparent to those skilled in the art in light of the following description and accompanying drawings.